A police officer in the western Canadian city of Edmonton was stabbed on Saturday evening by a man who then drove a U-Haul van into a crowd of pedestrians, wounding four, local media reported. The incidents are being investigated as 'acts of terrorism,' according to Edmonton Police Chief Rod Knecht. Knecht said in a news conference in the early hours of Sunday morning that there was an ISIS flag in the van. The police officer was not seriously wounded; the conditions of the four wounded pedestrians are not yet known.